Have a Classics Instruments Belara dash in my 55---having problems with oil pressure gauge--since day one it has been erractic and low---have worked with techs at Classic Instruments and have replaced the sending unit 3 times now---will work great for awhile--good oil pressure and then gradually get to about 25 PSI at 3000 rpm fully warmed up--needle will jump around a bit and shows an increase on deceleration--can hook up mechanical gauge and constant 45 PSI at 3000 rpm cruising and 25 at idle---getting ready to contact them again tomorrow and see what can be done--any insight for someone here--thanks